CN201408283Y

CN201408283Y - Optical lens group

Info

Publication number: CN201408283Y
Application number: CN2009201541837U
Authority: CN
Inventors: 陈文钦
Original assignee: Individual
Current assignee: Individual
Priority date: 2009-05-14
Filing date: 2009-05-14
Publication date: 2010-02-17
Anticipated expiration: 2019-05-14

Abstract

An optical lens assembly comprising, in order from an object side to an image plane: a first lens is a meniscus convex-concave aspheric lens with positive curvature index, a diaphragm is used to limit the light passing from the object side to the image plane, a second lens is a concave-convex aspheric lens, the central area of the second lens through which the optical axis passes has positive curvature index, and gradually slows down the positive curvature index towards the surrounding area, and the outermost effective area turns into negative curvature index, a third lens is concave relative to the central area surface of the object side and the image side, and the two sides of the non-central area are convex, the central area through which the optical axis passes has negative curvature index, and gradually slows down the negative curvature index towards the surrounding area, and the outermost effective area turns into positive curvature index. The utility model discloses accord with miniaturation and lightweight requirement, and the formation of image quality is good.

Description

Optical lens group

Technical field

The utility model relates to a kind of optical lens, relates in particular to a kind of optical lens group.

Background technology

Recently science and technology is flourishing, and with the lens group on digital camera or the mobile phone, all develops towards microminiaturized and light-weighted direction at present, and the camera lens of camera normally is made up of several eyeglasses, with correct for optical aberrations; And existing camera lens is all made with the spheric glass of glass material, and adopt the made lens group of spheric glass certainly will produce spherical aberration, proofreaied and correct and must increase eyeglass quantity, so will cause the volume of lens group to increase, moreover, the spheric glass of glass material still has not shock-resistant and easy to be damaged, and the heavier shortcoming of weight.

Therefore, as No. the 575184th, the novel patent of TaiWan, China and No. 200608078 disclosed lens group structure of TaiWan, China patent publication No., it is the different optical design that utilizes aspherical lens, and so as to improving image quality, and meet the requirement of lens group microminiaturization, and hence one can see that, and with the made lens group structure of aspherical lens, the optical design between its each eyeglass is the focus technology of present microminiaturized camera lens when design and research.

The utility model content

Technical problem underlying to be solved in the utility model is, overcomes the above-mentioned defective that prior art exists, and a kind of optical lens group is provided, and it meets microminiaturization and lightweight requirements, and image quality is good.

The technical scheme that its technical matters that solves the utility model adopts is:

A kind of optical lens group, be provided with one first lens in regular turn by object side to imaging surface, one aperture, one second lens and one the 3rd lens, it is characterized in that: these first lens, with the meniscus convex-concave non-spherical lens of convex surface towards object side and the positive bent refractive index of tool, the center thickness CT1 of these first lens is satisfied with the condition of 0.5mm＜CT1＜1.5mm, and the peripheral thickness ET1 that the effective sunlight of these first lens passes through is satisfied with the condition of 0.2mm＜ET1＜0.8mm, and this first lens object side surface aspherical shape R value parameter is L1R1, and imaging side surface aspherical shape R value parameter is L1R2, is satisfied with the condition of 0.25＜L1R1/L1R2＜0.45 between the two; This aperture is located between these first lens and second lens, after it enters this optical lens group in order to restriction light by object side, arrives the throughput of imaging surface; These second lens, with the concavo-convex non-spherical lens of concave surface towards object side, the middle section of this its optical axis process of second lens has positive bent refractive index, and its positive bent refractive index is slowed down in the zone around past more gradually, the effective coverage then changes into negative bent refractive index the most on every side, and the center thickness of these second lens and the 3rd lens is respectively CT2, CT3, and be satisfied with the condition of 0.5＜CT2/CT3＜1.5, and the thickness on every side that the effective sunlight of these second lens and the 3rd lens passes through is respectively ET2, ET3, and be satisfied with the condition of 0.7＜ET2/ET3＜1.3, and this second lens object side surface aspherical shape R value parameter is L2R1, and imaging side surface aspherical shape r value parameter is L2R2, is satisfied with the condition of 1.0＜L2R1/L2R2＜1.5 between the two; The 3rd lens, the curvature shapes of its object side and imaging side central area is all concavity, and on every side the both sides in non-central zone all contrary flexure transfer the non-spherical lens that curvature shapes is the biconvex shape to, the middle section of its optical axis process of the 3rd lens has negative bent refractive index, and its negative bent refractive index is then slowed down in the zone around past more gradually, and the effective coverage of outermost changes into and is positive bent refractive index, the center thickness CT3 of the 3rd lens is conditions of being satisfied with 0.5＜CT3/CT1＜1.5, and the thickness E T3 on every side that the 3rd lens effective sunlight passes through is satisfied with the condition of 0.7＜ET3/ET1＜1.3, and the 3rd lens object side surface aspherical shape R value parameter is L3R1, and imaging side surface aspherical shape r value parameter is L3R2, is the condition of being satisfied with L3R1/L3R2＞2.0 between the two.

Aforesaid optical lens group, wherein the d ray refractive index of first lens, second lens, the 3rd lens material is satisfied with the condition of 1.48＜Nd＜1.68, and the d light Abbe coefficient (Abbe Number) of these first lens, second lens, the 3rd lens material is satisfied with the condition of 55＜Vd＜65.

Aforesaid optical lens group, wherein all focal lengths of forming of optical lens group are f, and the focal length of these first lens, these second lens, the 3rd lens is respectively f1, f2, f3, and the relation between this each focal length is satisfied with following condition:

0.85＜f1/f＜1.15

0.5＜f2/f＜1.0

-1.0＜f3/f＜0。

Aforesaid optical lens group, wherein optical lens group is TL by the centre distance of this first lens object side surface till this imaging surface, and the ratio between TL and the f is the condition of being satisfied with 0.75＜f/TL＜0.95.

Aforesaid optical lens group, the focal length of optical lens group wherein, with the pass of this stop opening light-inletting quantity be F/no, and this optical lens group is satisfied with the condition of 2.0＜F/no＜3.3.

The beneficial effects of the utility model are that it meets microminiaturization and lightweight requirements, and image quality is good.

Description of drawings

Below in conjunction with drawings and Examples the utility model is further specified.

Fig. 1 is the structural representation of the utility model optical lens group

Fig. 2 is that the light of first lens of the present utility model is worn and penetrated synoptic diagram

Fig. 3 is that the light of second lens of the present utility model is worn and penetrated synoptic diagram

Fig. 4 is that the light of the 3rd lens of the present utility model is worn and penetrated synoptic diagram

The light that Fig. 5 is an optical lens group of the present utility model after assembling is worn and is penetrated synoptic diagram

Fig. 6 is the non-difference figure that checks and accepts of optical lens group of the present utility model optical characteristics when imaging

Fig. 7 is that difference figure is received in the distortion of optical lens group of the present utility model optical characteristics when imaging

Fig. 8 is that the sphere of optical lens group of the present utility model optical characteristics when imaging is received difference figure

Embodiment

Please cooperate and consult Fig. 1～shown in Figure 5, be the selected example structure of the utility model shown in the figure.

The utility model provides a kind of optical lens group, includes one first lens 11, an aperture 21, one second lens 31 and one the 3rd lens 4 in regular turn by object side 1 to imaging surface 3

1, wherein:

As shown in Figure 2, these first lens 11, be with the meniscus convex-concave non-spherical lens of convex surface towards object side 1 and the positive bent refractive index of tool, its surface near object side 1 is first aspheric surface 12 of convex, and be second aspheric surface 14 of concavity away from the surface of object side 1, the center thickness CT1 of these first lens 11 is conditions of being satisfied with 0.5mm＜CT1＜1.5mm, and the thickness E T1 on every side that the effective sunlight of these first lens 11 passes through is a condition of being satisfied with 0.2mm＜ET1＜0.8mm, and the aspherical shape R value parameter of these first lens, 11 object side surface (first aspheric surface 12) is L1R1, and the aspherical shape R value parameter of imaging side surface (second aspheric surface 14) is L1R2, is satisfied with the condition of 0.25＜L1R1/L1R2＜0.45 between the two;

This aperture 21 is located between these first lens 11 and second lens 31, after it enters this optical lens group in order to restriction light by object side 1, arrives the throughput of imaging surface 3;

As shown in Figure 3, these second lens 31, be with the concavo-convex non-spherical lens of concave surface towards object side 1, its surface near first lens 11 is the 3rd aspheric surface 32 of concavity, and be the 4th aspheric surface 34 of convex away from the surface of these first lens 11, the middle section of these second lens, 31 its optical axis processes has positive bent refractive index, and the zone around past more is to slow down its positive bent refractive index gradually, the outermost effective coverage then changes into negative bent refractive index, and these second lens 31 are to be respectively CT2 with the center thickness of the 3rd lens 41, CT3, and be satisfied with the condition of 0.5＜CT2/CT3＜1.5, and the thickness on every side that the effective sunlight of these second lens 31 and the 3rd lens 41 passes through is respectively ET2, ET3, and be satisfied with the condition of 0.7＜ET2/ET3＜1.3, and the aspherical shape R value parameter of these second lens, 31 object side surface (the 3rd aspheric surface 32) is L2R1, and the aspherical shape r value parameter of imaging side surface (the 4th aspheric surface 34) is L2R2, is satisfied with the condition of 1.0＜L2R1/L2R2＜1.5 between the two;

And as shown in Figure 4, the 3rd lens 41, its surface near these second lens 31 is the 5th aspheric surface 42, and be the 6th aspheric surface 44 away from the surface of these second lens 31, the curvature shapes of the central area of the 3rd lens 41 its object side surface (the 5th aspheric surface 42) and imaging side surface (the 6th aspheric surface 44) is all concavity, and on every side the both sides in non-central zone all contrary flexure transfer the non-spherical lens that curvature shapes is the biconvex shape to, the middle section of the 3rd lens 41 its optical axis processes has negative bent refractive index, and its negative bent refractive index is then slowed down in the zone around past more gradually, and the effective coverage of outermost changes into and is positive bent refractive index, the center thickness CT3 of the 3rd lens 41 is satisfied with the condition of 0.5＜CT3/CT1＜1.5, and the thickness E T 3 on every side that the 3rd lens 41 effective sunlights pass through is conditions of being satisfied with 0.7＜ET3/ET1＜1.3, and the aspherical shape R value parameter of the 3rd lens 41 object side surface (the 5th aspheric surface 42) is L3R1, and the aspherical shape r value parameter of imaging side surface (the 6th aspheric surface 44) is L3R2, is satisfied with the condition of L3R1/L3R2＞2.0 between the two.

And the optical lens group of forming by above-mentioned member of the present utility model, wherein the d ray refractive index of these first lens 11, second lens 31, the 3rd lens 41 materials satisfies following condition:

1.48＜Nd＜1.68

And the d light Abbe coefficient (Abbe Number) of these first lens 11, these second lens 31, the 3rd lens 41 materials satisfies following condition:

55＜Vd＜65

And all focal lengths of forming of this optical lens group are f, and the focal length of these first lens 11, these second lens 31, the 3rd lens 41 is respectively f1, f2, f3, and the relation between this each focal length satisfies following condition:

0.85＜f1/f＜1.15

0.5＜f2/f＜1.0

-1.0＜f3/f＜0

And this optical lens group is TL by the centre distance of this first lens, 11 object sides, 1 surface till this imaging side 3, and the ratio between TL and the f is satisfied with the condition of 0.75＜f/TL＜0.95;

And the 3rd lens 41 imaging sides (the 6th aspheric surface 44) of this optical lens group are between the imaging surface 3, can add parallel plane lens a slice or several pieces, do not change the focal length f that this optical lens group is formed, but can increase TL, so above-listed condition must be in the 3rd lens 41 imaging sides (the 6th aspheric surface 44) when not adding the parallel plane lens between imaging surface 3.

The pass of the focal length of the optical lens group that the utility model constituted and this stop opening light-inletting quantity is F/no, and satisfies following condition:

2.0＜F/no＜3.3

And utilize optical lens group provided by the utility model, and when its focal distance f is 3.6, aperture F/no is 2.8, drawing the angle is 66 °, and

Surf Type Rauids Thickness Nd Vd Conic

Obj ∞

1 Asphere 1.317 0.70 1.54 57.2 -2.302

2 Asphere 3.736 0.15 3.274

3 Stop 0.55

4 Asphere -0.837 0.50 1.54 57.2 -0.355

5 Asphere -0.685 0.05 -2.439

6 Asphere 19.797 0.55 1.54 57.2 84.759

7 Asphere 1.032 1.60 -6.417

8 Image ∞

And first lens 11 of the present utility model, second lens 31 and the 3rd lens 41 all meet the aspheric surface formula:

Z＝cr ²/1+〔1-(1+k)c ²r ²〕 ^1/2+Ar ²+Br ⁴+Cr ⁶+Dr ⁸+Er ¹⁰+Fr ¹²

Wherein, Z is for axially being worth along the Z of optical axis direction, and its aspherical lens is that the curved surface by above formula gained rotates around optical axis direction and forms, k is the tapering constant, c=1/k, r are clear aperature, and A, B, C, D, E, F are each aspheric high-order asphericity coefficient.

The coefficient of this first aspheric surface 12 is:

A＝0.040690105

B＝0.16113036

C＝-0.024556509

D＝0.080951504

E＝1.0802372E-05

F＝0.006955751

These second aspheric surface, 14 coefficients are:

A＝0.06633659

B＝-0.016292351

C＝0.28781439

D＝-0.5035064

E＝1.9444972E-06

F＝0.46072808

The 3rd aspheric surface 32 coefficients are:

A＝0.057155966

B＝-0.24244273

C＝0.17564233

D＝-0.043638362

E＝-0.12231296

F＝-0.4686445

The 4th aspheric surface 34 coefficients are:

A＝-0.065050952

B＝-0.20985749

C＝-0.035250715

D＝0.37778412

E＝0.00012680522

F＝-0.11142206

The 5th aspheric surface 42 coefficients are:

A＝-0.13807385

B＝0.66174097

C＝0.0054039467

D＝-0.0084241229

E＝0.0023121416

F＝-0.00021431647

The 6th aspheric surface 44 coefficients are:

A＝-0.25093048

B＝-0.0094271265

C＝-0.0017065541

D＝0.00025410189

E＝0.00049238319

F＝-8.5409169E-05

Whereby, can draw:

f1/f＝0.98 f2/f＝0.63 f3/f＝-0.72

f/TL＝0.878

L1R1/L1R2＝0.353

L2R1/L2R2＝1.222

L3R1/L3R2＝19.183

And by among Fig. 6 as can be known, its non-difference of checking and accepting of optical lens group provided by the utility model is less than 0.05mm; And by among Fig. 7 as can be known, distortion of the present utility model is received difference greater than negative 0.6%, and less than 0.6%; Again by among Fig. 8 as can be known, sphere of the present utility model is received difference less than 0.04mm.

Claims

1. An optical lens group is provided with a first lens, a diaphragm, a second lens and a third lens in sequence from the object side to the imaging surface, characterized in that:

The first lens is a crescent-shaped convex-concave aspheric lens with a convex surface facing the object side and having a positive refractive index. The central thickness CT1 of the first lens satisfies the condition of 0.5mm<CT1<1.5mm, and the first lens The peripheral thickness ET1 through which the effective light passes satisfies the condition of 0.2mm<ET1<0.8mm, and the aspherical shape R value parameter of the object side surface of the first lens is L1R1, and the aspherical shape R value parameter of the imaging side surface is L1R2, The two meet the condition of 0.25<L1R1/L1R2<0.45;

The aperture is arranged between the first lens and the second lens, and it is used to limit the amount of light passing through the imaging surface after entering the optical lens group from the object side;

The second lens is a concavo-convex aspherical lens with a concave surface facing the object side. The central region where the optical axis of the second lens passes has a positively curved refractive index, and the positively curved refractive index gradually slows down toward the surrounding area, and the outermost The effective area is converted into a negative refractive index, and the central thicknesses of the second lens and the third lens are CT2 and CT3 respectively, and satisfy the condition of 0.5<CT2/CT3<1.5, and the second lens and the third lens The surrounding thicknesses through which the effective light of the three lenses pass are ET2 and ET3 respectively, and satisfy the condition of 0.7<ET2/ET3<1.3, and the aspherical shape R value parameter of the object side surface of the second lens is L2R1, while the imaging side surface is non-spherical The r-value parameter of the spherical shape is L2R2, which satisfies the condition of 1.0<L2R1/L2R2<1.5;

In the third lens, the curvature shape of the central area on the object side and the imaging side is concave, and both sides of the surrounding non-central area are inversely turned into an aspheric lens whose curvature shape is biconvex. The central region through which the axis passes has a negative curved refractive index, and the surrounding area gradually slows down its negative curved refractive index, and the outermost effective area turns into a positive curved refractive index. The central thickness CT3 of the third lens is satisfied at The condition of 0.5<CT3/CT1<1.5, and the surrounding thickness ET3 through which the effective light of the third lens passes satisfies the condition of 0.7<ET3/ET1<1.3, and the aspherical shape R value parameter of the object side surface of the third lens is L3R1 , while the r-value parameter of the aspherical shape of the imaging side surface is L3R2, and the condition between the two satisfies the condition of L3R1/L3R2>2.0.

2. The optical lens group according to claim 1, characterized in that: the d-ray refractive index of the material of the first lens, the second lens, and the third lens satisfies the condition of 1.48<Nd<1.68, and the first The d-ray Abbe number (AbbeNumber) of the material of the lens, the second lens and the third lens satisfies the condition of 55<Vd<65.

3. The optical lens group according to claim 1, characterized in that: the focal length of the overall composition of the optical lens group is f, and the focal lengths of the first lens, the second lens, and the third lens are respectively f1, f2, f3, and the relationship among the focal lengths satisfies the following conditions:

0.85<f1/f<1.15

0.5<f2/f<1.0

-1.0<f3/f<0.

4. The optical lens group according to claim 3, characterized in that: the center distance between the first lens object side surface and the imaging surface of the optical lens group is TL, and the ratio between TL and f is The condition of 0.75<f/TL<0.95 is satisfied.

5. The optical lens group according to claim 1, characterized in that: the focal length of the optical lens group is F/no in relation to the amount of light entering the aperture aperture, and the optical lens group satisfies 2.0<F/ no<3.3 condition.